Bobbin stripper



March 11, 1969 s. ROSE 3,431,610

BOBBIN STRIPPER Filed Feb. 14, 1967 Sheet of :3

March 11, 1969 s, ROSE 3,431,610

BOBBIN STRIPPER Filed Feb. 14, 1967 Sheet 3 of s M: STANLG" 'Qos ited States Patent 7,045/66 US. C]. 2819 9 Claims Int. Cl. D03d 45/58 ABSTRACT OF THE DISCLOSURE A device for stripping waste yarn from a bobbin in which a cutter is mounted for longitudinal movement relative to the bobbin, the cutter having guide means for engaging the bobbin to maintain the blade a fixed distance from the bobbin surface to ensure complete stripping without damaging the bobbin surface.

This invention relates to bobbin strippers for automatically stripping waste yarn from bobbins.

Synthetic yarn is generally wound on to bobbins for a variety of textile applications and in many instances all the yarn on a bobbin is not used and the remaining waste yarn must be stripped therefrom before the bobbin can be re-used.

The bobbins are generally cylindrical of circular cross sectional shape and are formed of plastics material with end formations to permit them to be mounted for rotation. The yarn is wound tightly over the central region of the bobbin and it is most desirable that the surface of the bobbin should not be damaged during a stripping operation since thread subsequently wound thereon may be damaged or broken.

Various proposals have been made for automatic stripping apparatus. In one arrangement each bobbin carry ing waste yarn is moved longitudinally past a disc-like cutter the edge of which extends generally chordally of the yarn on the bobbin and which is set to skim along just above the surface thereof. In this construction the cutter in fact registers with the maximum possible dimension of the waste yarn so that very considerable force is required to strip the yarn from the bobbin. In addition there is a tendency for the cutter to be lifted away from the surface of the bobbin during the stripping operation so that it is necessary to force the cutter radially inwardly of the bobbin. In these circumstances and bearing in mind possible slight distortions in the plastics material of the bobbin it is found diflicult to adjust such apparatus so as continuously to strip waste yarn from a large number of bobbins without either leaving a thin layer of yarn on the bobbins or alternately cutting into the surface thereof.

In another apparatus Waste yarn has been stripped in a two-stage operation; a first stage being to cause relative linear movement between the bobbin and a radially disposed plough-like blade set to cut all but a few inner layers of yarn and a second stage being to remove these inner layers with a second cutter of the disc-like form referred to above. Although such an arrangement would reduce the force necessary for operation of the second cutter it still does not obviate the risk of damage to the bobbin surface.

A third proposal has been to drive a rotary cutter or abrasive disc disposed radially of the bobbin and cause relative linear movement of the bobbin and disc to cut the waste yarn. Although by driving the cutter the force required for effecting the linear movement is reduced the apparatus is complicated by the requirement for rotating the disc and furthermore the risk of damage to the surface of the bobbin remains.

It is accordingly an object of the present invention to provide an improved bobbin stripper which is mechanically simple and which reduces the risk of bobbin damage.

According to one aspect of the present invention there is provided a bobbin stripper comprising -a cutter, means for causing relative linear movement in the longitudinal direction of the bobbin between the latter and the cutter in order to strip waste yarn from the bobbin and guide means coupled with the cutter and engageable with the surface of the bobbin to maintain the cutter spaced therefrom a predetermined distance during said linear movement. Preferably the cutter is a blade disposed to cut through the minimum dimension of the yarn.

The above and other aspects of the inventions will now be described by way of example with reference to the accompanying drawings in which:

FIG. 1 shows in vertical section a cutter for a bobbin stripper,

FIG. 2 is a plan view of the cutter of FIG. 1.

FIG. 3 is an enlarged perspective view of the cutter with parts broken away and other parts omitted for clarity, and

FIG. 4 shows the mounting arrangement for the bobbin and cutter.

Referring to the drawings a cutter comprises a block 1 of generally rectangular formation and having its forward end chamfered as at 2 and being formed with longitudinal grooves 3 in its side walls for mounting pur poses. The block 1 has a central bore 4 counterbored at its upper end 5 and opening at its lower end into a counterbore 6 which in turn communicates with a cut-away portion 7. The wall of the central part of the cut-away portion 7 is outwardly flared to receive the flared lower ends 8 of a split collet and two halves of which are indicated at 9 and 10 and each of which terminates at its upper end in internally threaded half collars 11 and 12 which are loose sliding fits in the counterbore 6. An allen screw 13 is disposed in the bore 4 with its head in the counterbore 5 the lower threaded end engaging within the collars 11 and 12 to pull the collet into firm engagement with the block 1.

A generally rectangular blade 14 having sharpened front and lower edges 15 and 16 is disposed between the inner faces 17 and 18 of the parts 9 and 10 of the collet to be gripped thereby. The rear edge 17 of the blade 14 is firmly supported by shoulders on the two parts of the collet one of which is shown at 18. The lower sharpened edge 16 of the blade 14 is as shown in FIG. 1 inclined upwardly from its forward edge to be above the lower leading edges 19 and 20 of the collet parts 9 and 10. As seen in FIGURE 3 the edges 19 and 20 are square edges and extend on either side of the blade from closely adjacent the blade in a direction substantially normal to the plane of the blade. As shown in FIGS. 1 and 2. the forward part of the block 1 is formed with a bore 21 and recess 22 the former to receive a threaded rod 23 and the latter to hold captive a nut 24. The upper end of the rod is formed with a recess having an allen key and its lower end engages a forward part of the upper edge 25 of the blade 14 so that rotation of the rod 23 enables the height of the lower edge of the blade to be set relative to the lower leading edges of the collet parts 9 and 10. Furthermore, engagement of the lower end of the rod 23 with the blade 14 serves to hold the latter steady and prevent any tendency of its forward end to move upwardly in operation.

In operation, referring to FIGURE 4, the cutter is mounted on a stem 28 slidable in a vertical bore 29 of a holder 30 bolted to a mounting block 31. A spring 32 located in the bore acts on the top of the stem to urge it downwardly, the force of the spring being adjustable by means of a bolt 33 carrying a washer 34 engaging the top of the spring. The bobbin 35 has a surface 26 and, as shown in FIGURE 1, 27 represents waste yarn to be cut by the blade 14. The bobbin is held between two spaced supports 36, 37 projecting forwardly from a plate 38 slidable in a horizontal dovetail slot 39 in the mounting block 31 by means of a reciprocable piston and cylinder assembly 40 secured to the support 36. The spring 32 urges the cutter and bobbin together so that the lower leading edges 19, 20 of the collet parts 9 and 10 are maintained in firm engagement with the surface 26 and constitute guide means for the blade 14. The piston and cylinder assembly causes a relative linear movement between the bobbin and the cutter so that the blade 14 is presented substantially radially to the waste yarn 27 to strip the latter from the bobbin. As this linear movement progresses any irregularities in the surface of the bobbin cause relative radial movement between the latter and the cutter as a result of engagement with the bobbin by the collet parts so as to maintain the lower part of the blade 14 at a constant distance from the surface of the bobbin and substantially preclude the risk of damage thereto. As shown in FIG. 1 the lower edge of the blade 14 appears to be in contact with the surface 26 but in practice the blade will be set so that a very small gap will exist therebetween.

It is believed that the surface of the bobbin is distorted inwardly slightly so as to create a small gap between it and the innermost layer of yarn thus facilitating cutting of the latter by the blade 14.

It will be understood that the bobbins may be stationary while the cutter is moved relative thereto. The cut edges of the waste yarn flare outwardly past the curved outer surfaces of the collet parts and this waste yarn may conveniently be removed as the cutting operation proceeds by a suitably mounted suction device so that no particles of yarn remain either in the surrounding atmosphere or deposited on any of the working parts of the apparatus.

What I claim is:

1. A bobbin stripper comprising a cutter, means for causing relative linear movement in the longitudinal direction of the bobbin between the latter and the cutter in order to strip waste yarn from the bobbin and guide means coupled with the cutter and engageable with the surface of the bobbin to maintain the cutter spaced therefrom a predetermined distance during said linear movement, the guide means having a substantially square leading edge extending on either side of the cutter from closely adjacent the cutter in a direction substantially normal to the plane of the cutter so as to assist in stripping the yarn.

2. A bobbin stripper according to claim 1 in which the cutter is a blade disposed to cut through a minimum dimension of the yarn.

3. A bobbin stripper according to claim 2 in which the blade is generally rectangular having sharpened front and lower edges.

4. A bobbin stripper according to claim 3 in which the blade is held between the two parts of a split collet mounted in a supporting block.

5. A bobbin stripper according to claim 4 in which each part of the split collet has an internally threaded half collar at its upper end to be a loose sliding fit in a counterbore in the block the lower ends of the collet parts being flared and being accommodated within the outwardly flared lower end of the counterbore screw means passing through a bore in the block from the top thereof to engage the threaded half collars and the block being formed with a cut-away part to accommodate the front of the blade.

6. A bobbin stripper according to claim 5 in which a threaded rod is engaged within a threaded aperture in the forward part of the block to constitute an adjustable stop for the upper end of the forward edge of the blade.

7. A bobbin stripper according to claim 3 in which said guide means are constituted by the lower surfaces of the collet parts.

8. A bobbin stripper according to claim 7 including spring means for urging the guide means into the engagement with the bobbin surface.

9. A bobbin stripper comprising a cutter, means for causing relative linear movement in the longitudinal direction of the bobbin between the latter and the cutter in order to strip waste yarn from the bobbin, the bobbin being mounted on a block for sliding movement parallel to its axis and the cutter being mounted so that the cutter blade is presented radially to the bobbin surface, and guide means coupled with the cutter and urged into engagement with the surface of the bobbin to maintain the cutter spaced therefrom a predetermined distance during said linear movement, the guide means having a substantially square leading edge extending on either side of the cutter from closely adjacent the cutter in a direction substantially normal to the plane of the cutter so as to assist in stripping the yarn.

References Cited UNITED STATES PATENTS 2,609,876 9/ 1952 Bauer et al 28-19 3,092,889 6/ 1963 Hayes 2'819 3,108,354 10/1963 Hayes 28-19 3,137,913 6/ 1964 Hayes 2819 LOUIS K. RIMRODT, Primary Examiner. 

